1. Field of the Invention
The present invention relates to a switch with a magnetized rocker utilized in a part of a super-high frequency system such as an N-way power divider/combiner, a radio frequency transmission line and the like. More particularly, it relates to a switch with a rocker capable of being reliably opened or closed by an electromechanical operation.
2. Description of Related Art
Hereinafter, a conventional switch of prior art will be schematically described, referring to FIGS. 1 and 2.
As shown in FIG. 1, the conventional switch has a supporting plate 23, with a through hole in each corner thereof. A base-cover 26 is located under the supporting plate 23. Three connectors 31 to 33 are located under the base-cover 26. The conventional switch also has a rocker 25, which is made of metal that can be magnetized and disposed on the base-cover 26.
The supporting plate 23 has a first and second solenoids 21 and 22 disposed respectively at both ends of the bottom surface thereof; and a permanent magnet 24 is disposed between the two solenoids 21 and 22. Further, the first and second solenoids 21 and 22 respectively have a first and second bobbin cores 21a and 22a therein, so that the solenoids 21 and 22 can function as an electromagnet when a power is supplied.
The base-cover 26 has supporting bars 26a connected to each through hole of the supporting plate 23 on each corner thereof, and rocker supporting bars 26b to support the rocker 25 on both sides of the center portion thereof. Each rocker supporting bar 26b has a through hole on upper portion thereof. Therefore, when the rocker 25 is disposed on the base-cover 26, the rocker 25 is supported by a rocker pin 35, which slips into the through hole of the rocker supporting bar 26b and the rocker 25. This is to ensure that predetermined space is maintained between the rocker 25 and the solenoids 21 and 22 and between the rocker 25 and the permanent magnet 24.
In this case, the rocker 25 seesaws about the rocker pin 35 by a predetermined angle.
In the conventional switch, the rocker 25 is magnetized by the permanent magnet 24 to cycle in S-N-S pole. That is, when power is supplied to one of the solenoids, the magnetized rocker 25 is tilted by the influence of a magnetic field from the solenoid. Further, the rocker 25 is always pulled in an upward direction by the permanent magnet 24 disposed on the bottom surface of the supporting plate 23.
The rocker 25 has a plate spring 27 disposed on the lower portion thereof. The base-cover 26 has two dielectric pins 28 inserted at both end portions thereof. When the rocker 25 is tilted, each dielectric pin 28 is pushed by the plate spring 27 in a downward direction of the base-cover 26. Each dielectric pin 28 is surrounded by a spring 29. The spring 29 provides a restoring force to the dielectric pin 28, so that the dielectric pin 28 returns to its original position when the pressure by the plate spring 27 is removed. Each dielectric pin 28 has a reed 30, which contacts with two connectors 31 and 32 or 32 and 33 on the lower end portion thereof.
In conjunction to the conventional switch constructed as described above and as shown in FIG. 2, the following explanation applies. When the power is supplied to the first solenoid 21, S pole (South Pole) occurs in the lower portion thereof. At this time, since the left portion of the rocker 25 is an S pole, the first solenoid 21 repels the left portion of the rocker 25 in the downward direction. At the same time, the right portion of the rocker 25 is moved in the upward direction and is contacted with the second solenoid 22. In this case, the left portion of the plate spring 27 pushes the dielectric pin 28, positioned in the left side of the basecover 26, so that the left reed 30 is contacted with the first and second connectors 31 and 32.
On the contrary, if an operator supplies the power to the second solenoid 22, the right portion of the rocker 25 having S pole is moved in an downward direction by the described principle as above. Also, the right portion of the spring plate 27 pushes the dielectric pin 28, so that the right reed 30 is contacted with the second and third connectors 32 and 33. In this case, the restoring force of the spring 29 disconnects the left reed 30 from the first and second connectors 31 and 32.
In both cases, the rocker 25 is always pulled up by the magnetic field of the permanent magnet 24, disposed in the center portion of the supporting plate 23.
Therefore, the conventional switch requires sufficient power to overcome the friction force between the rocker pin and the through hole of the rocker supporting bars when the switch is operated. Further, the movement of the rocker puts stress on the center portion of the plate spring @ (FIG. 2), which has a thickness of 0.1 mm-0.15 mm. When the stress is persistent, there is a problem that fatigue happens in the area @. Furthermore, the contacted portion of the plate spring can be plastic-deformed while the plate spring is pushing one of the dielectric pins for a long time. In this case, the connectors cannot be properly contacted reliably by the reed because the pressure provided by the dielectric pin can be weakened due to the plastic deformation of the plate spring.